CVE-2025-14133 is a stack-based buffer overflow vulnerability identified in several Linksys range extender models (RE6500, RE6250, RE6300, RE6350, RE7000, and RE9000) running specific firmware versions (1.0.013.001, 1.0.04.001, 1.0.04.002, 1.1.05.003, 1.2.07.001). The vulnerability resides in the AP_get_wireless_clientlist_setClientsName function within the mod_form.so module. By manipulating the argument clientsname_0, an attacker can overflow the stack buffer, potentially overwriting the return address or other control data. This can lead to arbitrary code execution with elevated privileges on the device. The vulnerability is remotely exploitable without requiring authentication or user interaction, making it highly dangerous. The CVSS 4.0 base score of 8.7 reflects the high impact on confidentiality, integrity, and availability, combined with low attack complexity and no privileges or user interaction needed. Despite early notification, Linksys has not issued patches or advisories, and a public exploit is available, increasing the likelihood of exploitation. The affected devices are commonly used in home and small business environments to extend wireless coverage, which may serve as entry points into larger networks if not properly segmented.

For European organizations, this vulnerability poses significant risks. Compromise of Linksys range extenders can allow attackers to execute arbitrary code, potentially gaining control over the device and using it as a foothold to infiltrate internal networks. This can lead to data breaches, interception of network traffic, disruption of wireless connectivity, and lateral movement to more critical systems. Small and medium enterprises relying on these devices for network extension may be particularly vulnerable due to limited security monitoring. The lack of vendor response and available exploit increases the urgency. Critical infrastructure sectors using these devices could face operational disruptions or espionage risks. Additionally, the vulnerability could be leveraged in botnet campaigns or as part of multi-stage attacks targeting European networks.

1. Immediately identify and inventory all Linksys range extenders in use, focusing on the affected models and firmware versions. 2. Disable remote management interfaces on these devices to reduce exposure. 3. Segment network architecture to isolate extenders from critical systems and sensitive data. 4. Where possible, replace affected devices with models from vendors providing timely security updates. 5. Monitor network traffic for unusual activity originating from these devices, including unexpected outbound connections. 6. Employ intrusion detection/prevention systems tuned to detect exploitation attempts targeting this vulnerability. 7. Apply strict access controls and network segmentation to limit attacker movement if a device is compromised. 8. Engage with Linksys support channels for updates or advisories and follow security community channels for emerging mitigations. 9. Consider deploying endpoint detection on connected clients to detect lateral movement attempts. 10. Educate IT staff about this vulnerability and ensure incident response plans include scenarios involving compromised network extenders.